Printing telegraph system and apparatus



Feb. 6, 1951 L. M. POTTS PRINTING TELEGRAPH SYSTEM AND APPARATUS l4Sheecs-Sheet 1 Filed June 4, 1947 INVENTOR LOUIS M. POTTS, DECEASED BYMARTHA W.-C. POTTS, EXECUTRIX 7 ATTORNEY Feb. 6, 1951 L. M. POTTS2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 1947 14Sheets-Sheet 2 FIG. 2

IN A NTOR 4 LOUIS M. POT ,DECEASED MARTHAWC.POTTS,EXECUTRIX' Z1 WMATTORNEY Feb. 6, 1951 L. M. POTTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 1947 14Sheets-Sheet 3 lNVENTOR LOUIS M. 'POTTS, DECEASED MARTHA W. G.POTTS,EXECUTRIX ATTORNEY Feb. 6, 1951 1.. M. POTTS PRINTING TELEGRAPHSYSTEM AND APPARATUS l4 Sheets-Sheet 4 Filed June 4, 1947 Illli "II"lllllllllllllllllll ill-"9' l l N l an R Feb. 6, 1951 L. M. POTTS2,540,287

- PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 194? 14Shets-Sheet s INVENTOR 9 LOUIS M. POTTS,DECEASED (0 BY MART%\ W.C.POTTS,EXECUTR|X M WATTORNEY L. M. POTTS PRINTING TELEGRAPH SYSTEM ANDAPPARATUS l4 Sheets-Sheet 6 Feb. 6, 1951 Filed June 4, 1947 INVENTORLOUIS M. POTTSQDECEASED MARTHA W. 0. POTTS,EXECUTRIX ATTORNEY Feb. 6,1951 M. POTTS PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 194714 Sheets-Sheet 7 INVENTOR M. POTTS, DECEASED MARTHA w. c.POTTS,EXECUTR|X u. 4: 'BLOUIS 14 Sheets-Sheet 8 L. M. POTTS PRINTINGTELEGRAPH SYSTEM AND APPARATUS Feb. 6, 1951 Filed June 4, 1947 nwn Nmmown INVENTOR LOUIS M. POTT$,DECEASED MARTHA w. c. POTTS,EXECUTRIXATTORNEY Feb. 6, 1951 M. POTTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 1947 14sheets-sheet 9 INVENTOR LOUIS M. POTTS,DECEASED BY MARTHA W 0.POTTS,EXECUTRIX Z21 WM ATTORNEY Feb. 6, 1951 L. M. POTVTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 1947 l4Sheets-Sheet 10 362 FIG. I4 I 562" FIG. l5

I 240 INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. C. POTTS, EXECUTRIX BYKim WM ATTORNEY Feb. 6, 1951 M. POTTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed-June 4, 1947 14Sheets-Sheet l1 FIG. I9

INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. C. POTTS,EXECUTRIX Feb. 6,1951 L. M. POTTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 4, 1947 14Sheets-Sheet 12 FIG. |6A

FIG. ISA FIG. I7A

FIG. l8A 292-A 240 264 a I I l I I I I l I I I I I I I I I I y INVENTORLOUIS M. POTTS, DECEASED BY MARTHA W. C. POTT$,EXECUTRIX Z17 WM ATTORNEYFeb. 6, 1951 L. M. POTTS 2,540,287

PRINTING TELEGRAPH SYSTEM AND APPARATUS Filed June 1947 14 Sheds-Sheet13 INVENTOR LOUIS M. POTTS, DECEASED MARTHA W. .C. POTTS,EXECUTRIXATTORNEY 14 Sheets-Sheet 14 o EFT INVENTOR ,DECEASED ARTHA W. O. POTTSEXECUTRIX WMTTORNEY LOUIS M. POTTS mom 7 L. M. POTTS PRINTING TELEGRAPHSYSTEM AND APPARATUS Feb. 6, 1951 Filed June 4, 1947 patented Feb. 61951 PRINTING TELEGRAPH. SYSTEM AND APPARATUS Louis M. Potts, deceased,late of Evanston, Ill., by Martha W. C. Potts, executrix, Evanston,Ill., assignor to Teletype Corporation, Chicago, 111., a corporation ofDelaware Application June 4, 1947, SerialNo. 752,512

--This invention relates to printing telegraph systems-- and apparatus,and particularly to systems wherein printing telegraph apparatus is usedfor recording code marks on a page form and the form is subsequentlyscanned by a photoelectric transmitter which transmits signalsaccordingly.

An object of the invention is to provide a printing telegraph systemutilizing printing telegraph apparatus for reproducing on a page formboth printed characters and corresponding code marks, and in which thecode marks so provided are scanned by a photoelectric transmitter fortransmission purposes. 1. Another object of the invention is to provideprinting telegraph apparatus for recording code marks on the rear of apage form which corresponds to related printed characters reproduced onthe front of the page form.

An additional object of the invention is to provide a printer whichconverts one equal length code having shift signals to another equallength code having no shift signals.

Another object of the invention is to providephotoelectric transmittingapparatus which scans a page form having code marks thereon, lineby.line, and transmits signals according to the code marks so scanned.

A further object of the invention is to provide a photoelectrictransmitter which converts the signal representations of one equallength code-into the signal representations of another equal length codewith automatically inserted shift signals.

:z-Still another object of the invention is to provide a photoelectrictransmitter which automatically transmits a carriage return signal.

feature of the invention is the use of a traveling projector in aphotoelectric transmitter which after completing the scanning of a lineofcode marks on a page form is automatically returned to its beginningof line position preparatory to scanning the next line of code marks.When the projector reaches the beginning of line position-the page formis advanced to place the next line of code marks in scanning position.Another feature of the invention is the use of. a pivoted projector forscanning control form indicia wherein the focal length of the projectoris. automatically adjusted according to the area of the form beingscanned.

Other objects, features, and advantages of the invention, although notspecifically recited above, will become apparent as the invention islater described in detail.

Claims. (Cl. 178-23) One form of page printer used in the presentinvention is of the type shown in the patent of A. H. Reiber, No.2,247,408, dated July 1, 1941. The selector mechanism disclosed in theReiber l patent has been modified so that in addition to controlling thestop or printing position of a type wheel, it also establishes aselection for a series of six code mark printing elements which causeprinted code marks to be impressed on the rear of the page form in avertical line with, and above, corresponding printed charactersreproduced on the front of the page form. Five of the code mark printingelements are operable from the selector mechanism proper while the sixthcode mark printing element is controlled by the position of the caseshifting mechanism. For code mark inking purposes, either a stamp pad oran ordinary inking ribbon is used. With each code mark printingoperation, two smaller code marks are universally printed for controlpurposes when the code marks are scanned by the photoelectrictransmitter. One of the feed marks is centralized with respect to thecode marks while the other is slightly offset to the right (when lookingat the rear of the page form) so that there is always a feed mark in themargin for beginning of line control purposes.

A second form of page printer used in the present invention is of thegeneral type shown in the patent of Morton et al., No. 1,904,164, datedApril 18, 1932. A secondary selector mechanism .for code mark printingis provided with this page printer, which is controlled from the printervanes, and is movable with the type basket. Again the code marks areprinted on the rear of the page form in a vertical line above thecorresponding printed characters reproduced on the front of the pageform. Each of the page printers utilized in the present invention, inresponse to a five unit code signal prints a six unit code and, thus, ineffect acts as a translator.

The photoelectric transmitter includes a pivotally mounted projectorwhose free end moves across a line of code marks reproduced on a pageform, stopping at each code combination to transmit the signal and thenresuming its travel to the next code combination. When the end of theline is reached, the projector is automatically returned to thebeginning of line position as a new line of code marks is fed intoscanning position. Sequential transmission of thecode impulses and thestart-stop impulses by operation of a photoamplifier tube, is ob tainedby means of a scanning disc. The scanning disc consists of an opaquecircular plate having arcuate transparent areas arranged at differentradial distances and in different angular positions about the centerpoint. These arcuate areas represent the six elements of the codecombination and the stopimpulse. A start impulse is a no current impulseand therefore no transparent area is provided in this case, the opacityof the circular plate being relied upon to send the start impulse. Thefeed marks are scanned by a continuous transparent ring of the scannindisc when a shutterv is in one of its two positions, and at "this timethe code marks are blocked. In its, other postion, the shutter permitsscanning of the code marks and blocks scanning of the feed marks. Asuitable circuit arrangement is provided for use with this photoelectrictransmitter for the transmission of a six unit code signal.

The, invention also provides. a modified form of transmitter whichconverts the six unit code into a five unit code with automatically,inserted shift and unshift signals and carriage return signals. However,it. should be pointed out that the. photoelectric transmittingapparatusdis-., closed herein, is designed to be used either in the sixunit code system, or in the five unit code system. A different circuitarrangement is used in conjunction with the photoelectric transmitterdesigned to transmit five unit code signals.

In each of the photoelectric transmitters, provision is made shouldabnormal spacing occur between code mark combinations, When thiscondition is encountered, the stop impulse between characters isprolonged and thus no detrimental results will occur at the receivingend of the line since in start-stop telegraph practice the receiving camsleeve would be held in its: stop position until a start impulse isreceived. The transmission of the code combination of the abnormallyspaced characters is in this way delayed but is transmitted'intactwithout impairing transmission.

A. more ready comprehension of the invention maybe had byreference tothefollowing detailed 7 description when read in conjunction with thedrawings wherein:

' Fig. 1 is a partial eleyationalview of amodified. page printer. of thetype disclosed in the Reiber patent takenlat the right-hand sidethereof;

Fig. 2 is a detailedview of. the sameprinter, particularly illustratingportions of the code mark printing mechanism involved in. the presentin-. vention;

Fig. 3 is a partial plan view. of the samepage printer;

' Fig. 4 is a detailed view of the selector. slides provided in thepresent invention;

Fig. 5 is a detailedview of the feed mark printing leversutilized in thepresent invention;

Fig. 6 is a detailed view of thesame page printer showing the use of astamp pad instead ofa ribbon for inking purposes;

' Fig. 7 is a plan view of the pageprinter wherein the stamp pad is usedin .place of theribbon for inking purposes;

Fig. 8 is a partial front view of a modified printer of the type shownin the Morton etal. patent;

Fig. 9 is a partial end view of the same printer;

Fig. 10 is a partial plan view, ofthe same p in e Fig. 11 is a detailedview of a code ing lever;

Fig. 11a is a detailed view of the feed mark printing lever;

Fig. 12 is a plan view of the photoelectric transmitting. apparatus withparts broken away and parts omitted to avoid confusion in the drawings;

Fig. 12a is a detail of a braking mechanism which forms part of thephotoelectric transmitter;

Fig. '13 is a section view of the photoelectric transmitter taken on theline l3l3 of Fig. 12;

Fig. 14 is a section view of the transmitting apparatus taken on theline l4l4 of Fig. 13;

Fig. 15 is a partial plan view of the transmitting apparatus devotedparticularly to the feeding of the page form;

Fig. 16 is a detailed view of the scanning disc used in connection withtransmission of a six unit code;

Fig. 16a is a detailed view of the scanning; disc used in connectionwith transmission of; a; five, unit code;

Fig. 17 is a rear view of apage form illustrating: printed code markcombinations and'feed marks;

Fig. 17a is a view identical with that showI-rin Fig. 17 and duplicatedfor convenience in reading the specification;

Fig. 18- is anenlarged detail; view ofthe end of the projector used forsix unit code trans.-.. mission particularly for the purpose of showingthe code mark and feed mark openings;

Fig. 18a is an enlarged detail view. or the end of the projector usedfor five unitcode. trans: mission particularly for the purpose ofshowing the code mark and feedmark openings;

mark print- Fig. 19 is a detail of the shutter. used: for six unit codevtransmission;

Fig. 19a is a detail of; the shutter used. for-alive unit codetransmission;

Fig. 20 is a circuit arrangement used for six-unit code transmission;and

Fig. 21 is a circuit arrangement: usedxfor-five. unit code transmission.

Referring now particularly to Figs. 1: toJlj't-he: first form of pageprinter used inthe presentinvention will, be. described; it: being.understood that the page printer. now being considered isoi the,general. type disclosed in the hereinbefore mentioned Reiber. patent.Numeral 5|v (Fig. 1*)? represents a. selector cam assembly which bymeansof a sword andv T-lever. selector. mecha-v nism (not shown), controlsasettingof-fi-ve selec tor levers 52 pivoted at 50 (Fig. '7),as isfully.

shown and described in the Reiber patent; Levers 52 are bifurcated at53zfor ar-ticulationto associ ated bell crank transferlevers 54, which.areenr. gaged in. notches Bil-:otcode.discselector 56-ito therebycontrol the setting thereof; Positioning of code disc selectors 56 inturn governsthe selec-'- tion of a. particular stop pin 51 whichdetermines the stop position of type wheel 55 in a manner. well known inthe art.

Aftenthe type wheel-i5 has been brought to rest, one ofthe. type pallets58 carried-whereby, ineither theupper or-lower-row of'type. pallets isengaged by a. printihammeiv 59 to causethe printing of avselectedtcharacter. The. row;- or. type. pallets selectedby the printhammeriflfils determined by the..case shiftposition of---a..-.ty.pevwheel supporting frame 6lat the-top of'whlchl rests the typewheel 55. Ineachcycleiotoperae tion,.a lever 62 operable fromacam, shown inr-theReiber patent, movesupward :and by meansoispring 63 draws frame 6! alsoin an upward'direcs tion, causing the frame to lift the type wheel toits selected case position. A lug Bicarried by frame 6I may engageeither shoulder 66 or shoul der 61 of a horizontal slide 68 to therebylimit the upward movement of frame 6I to one or the other of its casepositions. Horizontal slide 68 i positioned under the control offunction levers (not shown) either to its rightward or lower caseposition, or to its leftward or upper case position as is fullydescribed in the Reiber patent. When slide 68 is in its rightwardposition, type pallets 58 of the upper row may be operated by the printhammer 59 and when slide 68 is in its leftward position, type pallets 58of the lower row are operated by the print hammer 59.

Returning now to the selector mechanism, the five selector levers 52 areeach modified in ac cordance with the present invention to include arounded projection 89, engaging the notches II of five associated slides12 which are suitably mounted for sliding motion on pins I3 and'lfi. Asixth slide 728 is also provided which is of slightly difierentconfiguration than slides 72 and is mounted on pin I3 at the top of theslides I2. Formed only on the slide 128 is a notch 74 designed to beengaged by the upper end of a lever I6 which is pivoted at H, the lowerend of 16 rests in notch I8 of previously identified horizontal slide88, and thus slide 12S is shifted to the case position occupied byhorizontal slide 68 while the remaining five slides 12 are under controlof a sword and T-seector mechanism (details of which are not shown).

Each of the slides I2 and 12S are provided with a single progressivelyarranged projection I9, which engages in a notch (not shown) of a seriesof vertically extending rods 82, 828, suitably mounted in the apparatusfor rotatable movement. The upper end of each rod 82 is provided with anotch 83 engageable by a projection 84: of slides 86, 89S, mounted forslidable movement on pins I5 which are in alignment with pins 13. Formedon each of the upper slides 86, 86S, is a bifurcation 81, in which isnested an arm of an associated bell crank transfer lever 85, pivoted at88 and having its other arm in engagement with a notch 89 of a thirdseries of slides 9!, 91S.

Slides SI and 9IS are each nested for slidable movement withinassociated code mark levers 92-I to 92-5 which are pivoted about the rod93. Slide 9IS is related to the sixth code lever.

92-6, since by means of the page printer now being considered, a fiveunit code may be transposed into a six unit printed code. Slides 9I-I, 9IS are guided within their associated code mark levers 92! to 92-6 bymeans of the retaining portion 94 and 95 of the code mark levers. Eachof the slides 92-I to 92-6 are provided with printing projections 91.Slides 9!, 9i S are provided with interfering projection 98, which maybe shifted into the path of auxiliary print hammar 99 carried by themain print hammer 59 in response to a marking impulse or will be shiftedout of the path of auxiliary hammer 99 in response to a spacing impulse.A feed mark lever IOI (Fig. 5) having two small feed mark projectionsI02, is also mounted on red 93 and includes an interfering projectionI03 which is universally engaged by auxiliary print hammer 99. Becauseof the universal operation of feed mark lever IOI, no slide is providedin this case to govern its operation. Leaf springs I00 normally urgelevers 92-I to 92-9 and lever I9! towards the front of the apparatus.

Referring again to the lower slides 12, 12S, it

is to be observed that the slide 128 is the topmost of the five.However, its related upper slide 858 is connected to vertical rod 828 soas to be at the bottom of the upper slides 86. It is apparent from aninspection of either Fig. 2 or Fig. 6 that the code mark levers 92-I to92-5 are arranged in that order from top to bottom and that the feedmark lever IOI is interposed between levers 92-3 and 92-4.

The auxiliary print hammer 99 is slidably carried on the print hammer 59by means of pins I02 which ride in a slot I03 formed on print hammer 59.A spring I04 interconnects the auxiliary print hammer 99 with the mainprint hammer 59 to urge the auxiliary hammer 99 in a direction towardsthe code mark printing platen I96. This provides a slight yield in theparts which insures that when a character is printed by the operation ofthe main print hammer 59 engaging a selected type pallet 58,corresponding code marks will be printed by operation of the printhammer 99. In other words, auxiliary print hammer 99, by reason of thisconstruction, will always travel far enough to cause the printing ofcode mark impressions. To suppress printing during shift and unshiftoperations, print hammer 59 is provided with a lug I07 (Fig. 2) whichmay engage either of two lugs I08 (only one of which is shown in thedrawing) carried by the type wheel 55 and be blocked thereby. Thus,according to the position assumed by selector lever 52, and by lever 16,which is under the control of horizontal slide 68, code mark levers 92-Ito 92-9 will be selectively operated by auxiliary print hammer. 99according to whether or not their associated interfering projections 91are positioned in the path of the auxiliary print hammer.

Mounted on the carriage I09, is a shaft III which supports the mainplaten H2 in the usual manner. Added to shaft II I is a gear I I3 whichis in mesh with an intermediate gear m which in turn drives the gearII6. This latter gear is attached to shaft II! which carries theauxiliary paper feed rollers I I8. Cooperating with feed rollers II8 arepressure rollers II9 carried by a shaft I 2! rotatably supported ateither end on the bell crank I 22 which are pivoted at I23, springs I25(only one of which is shown) urge bell crank I22 in a counterclockwisedirection as viewed in Fig. 2 to bias the pressure rollers II9 iritoengagement with auxiliary paper feed rollers In Figs. 1, 2, and 3 it iscontemplated that an inking ribbon I24 is to be used as an inkingmedium, while in Figs. 6 and 7, a stamp pad I26 is used for inkingpurposes. Otherwise, the disclosure of Figs. 6 and '7 is consistent withthe disclosure of Figs. 1, 2, and 3. The ribbon I26 is fed betweenspools I2! in any convenient manner and said spoolsmay be provided withany conventional ribbon reverse mechanism. The ribbon is fed across therear of the page form adjacent to platen I06. When multiple copies arebeing printed, the original or top form, is fed over the auxiliary feedrollers II8 and reccives code mark impression while the other copies maybe fed out over the standard platen II2. It will be understood that thefeeding pressure applied by rolls I I8 and H9 to the top page form willnot be greater than the feeding pressure applied by the platen II2, sothat platen II2 dominates the advancement of the paper. The rate of feedprovided by rolls I I8 and H9 may be approxi: mately the same, orslightly greater than the rate of feed provided by platen H2 in order toamass maintain'the page form 240 taut. In Figs. 6 and '7, the inkingribbon is dispensed with and a stamp pad "I26 is substituted therefor inthe position formerly occupied by the platen I 865.

With particular reference to Figs. 8 to 11, a second form of code markpage printer contemplated by the present invention will be described, itbeing understood that this printer is of the general type shown in thispatent of Morton et al.,

No. 1,904,164, dated April 1-8, 1933, with modifi- :moves to one caseposition in response to a shift signal and remains in such positionuntil an un-- shift signal is received. Vanes i5ll to I-5I-5 are eachengaged at I52 by one arm of bell crank 153 which pivots at i5 i on thetype basket ISEito :select a character for printing as is also fully described in the Morton et a1. patent. The type basket is movable acrossthe front of the printer on rollers I56, 551 which ride on the rod i5ein amanner well known in the art.

Suitably attached to the type basket M5 is a bracket I59 which pivotallysupports at I5I a series oflevers IfiG- l to i6 i6. Also pivoted atpoint IBI is a feed control lever IMF of a different configuration thanlevers IEi| 'to 164+6, which controls the printing of the feed marks.Each of the levers fib il-4 to lt i6 are guided in slots of a comb I66carried by the bracket I59 and are provided with individual lugs 461,which rest against the rear of associated vertically extending leverslB8I to Iii-8'. Levers 168-4 to I68E are also pivoted at I61 and areinterconnected with associated levers I64I to I S I5 by means ofconnecting springs I'II. Normally the projections I72 carried by thevertically extending levers Its-I to I686 rest against a backstop I13carried by the bracket I59. Lever IB4F and a lever Ilia-F are similarlyinterconnected by means of a spring Ill. Levers I52| to I62-& are eachsupported at I63 on associated levers I 64-I to I64-8and.are normallyurged in a counterclockwise direction by means ofsprings I14. The topsof the levers I 62-.I to 32-6 are guided in slots of a comb I I6 carriedby bracket I59. A spring Ill normally urges the lever Hi l-F about thepivot Iiil. Mounted on frame IBI, which 'by means of a downwardlyextending arm I33 is suitabl attached' to' the type basket I55, areaseries of slides 'I' 8 2-F and I82--I to 32-43. Slides liiiZ-F andIj82-I to [82-45 are slidably mounted on the pins I83 and I84 and aredesigned to be engagedat their notched 'portions I36 by associatedvertically extending levers I6B-F and I6B-I to i68+6.

Carried at either side of the platen carriage 185' are brackets G86,I87, which support the end of*guide"rods I88, I89,"designed tobe'traversed byaframelsl" by means of its flanges 192 and I93. FrameI'SII carries a shoulder screw which rests'in the bifurcation 596 ofan'upwardly extending arm'li-ll which is carried by the type basket I55.Thus, although the frame'lii may be shifted vertically during a caseshifting operation, bifurcation I95 of arm 59? by reason of itsengagement with shoulder screw I94 'will permit the frame'ISI to followthe movements of the type "basket I55. Pivotally mountedat 209 on theframe; I9I are a seriesof code mark levers 'I'98=I toI98-6anda feed marklever i98-=F use (Fig. 11 whichare normally urged towards the front ofthe apparatus Joy-individual springs 2l0. Lever I98-F'-is provided withtwo printing elements I99 while the code mark'levers I-98I to res-a2 areprovided with a single larger marking projection 201 which is in avertical line above the character printing position. Each of the slidesIBZ-F, I82'l to I826 is provided with 'anupper-interferingprojection-'202U and a lower interfering projection 202L either of whichis operable, dependingupon the case position of the platen to which theframe I9I has been moved; Projections ZEIQU are longer than projections2021i since, when the platen is shifted to its upper case position, itpivots and moves a slight distance away'from the front of the machine.It is therefore necessary that in its upper case position, the upperproject-ions 202U be long enough to en'- gage projections 2050f theirassociated code mark levers or code feed levers as the case may be;Projections 205 ofeach code mark lever -I9 8--I to I-9 8-6 and feed marklever E98-F are progressively arranged'so that eachinterferingprojections ZBZU, '202L of associated slides i82- I to i82-6,I82-F, may operate only its corre-'- sponding lever.

On each forward movement of the printing bail in each cycle of operationan extension 286 extending therefrom, is designed to engage the tail endof lever 164-4? causing it to pivot in a counterclockwise direction asviewed in Fig. 9 and by means of its spring ill to carry its associatedvertically extending lever I'Bfi-F to its real-most position. .As leverI68-F moves rearwardly it carries its associated slide I82-F also to therear which by means of projection 2fl2U or 2$2L dependingon the caseposition of the apparatus, universally operates the code feed markinglever Hit-F in each printing operation. Further, as extension 206 .ofthe printing bail moves forwardly, it'engages the upper edge of leversI'6,2 'I to I52t and causes these levers to pivot harm; lessly in aclockwise direction as viewed in Fig. 9, if their projections .28? donot bump against an associated vane I.5II to I5I6. However, if theprojections 201 of levers I62I to M2 6 bump against the printer vanesI5II to I5I-6 as when they have assumed their marking .01 clockwisepositions, the vanes will serve as a fulcrum point and cause bailextension 206 to carry selected levers I64I to I5 i--5 in an outwardorcounterclockwise direction as viewed in Fig.8 and through theirsprings Ill to pivot associated levers IB8I to I586 in acounterclockwise direction. In this manner, selector levers I82,I toI825 will move'towards the rear of the machine slightly andengage eithertheir projections 2521) or 2tl2L, according to the case shift posi tionof the apparatus, with associated code mark levers I98I to |-ea c. Itwill be understood that feed mark lever I98-F will always be operatedduring a printing operation. As described in'the aforementioned Mortonet al. patent, during certain function operations, printing bailextension 266 will not move a full stroke, and therefore, the'carriagewill not space and no code or feed marks will be printed under suchconditions. However, when aspace signal is received, that is, a letterspace'signal, bail 206will make a full stroke and cause operation ofcode mark lever I98'3 and at the same time feed mark lever I98F. 'But atthis time, no corresponding printed character is printed, since nocharacter is providedin' the printer for this operation. It

9 is desired that the sixth code mark be printed when sixth vane ll-6 isin its counterclockwise or figures shift position and, therefore, inthis case, projection 281 of lever l628 will engage against vane l5|-6only in this position. The projections 281 of the other levers l62! to"52-5, however, engage against vanes |5|-l when the latter are in theirclockwise or marking positions. No sixth code mark will be printed withvane l5l6 in its clockwise or letters shift position.

Attached to the platen shaft 2 is a gear 212 which is in mesh with agear 2 I3 which in turn drives the gear 2l4. Gear 214 is mounted onshaft 2|6 which carries an additional paper feeding roll 211. Auxiliarypaper feeding roll 2|1 is engaged by a pressure paper roll 2|8 carriedby lever 2!!! which is urged about the pivot 22! by means of a spring222. For accomplishing code mark printing impressions, a sheet of carbonpaper 226 is suitably fed around the lower end of a platen 221, with itsinking face adjacent to the rear of the topmost page form when multiplecopying is being performed, and is fed together with the top copybetween the pre sure roller 2 I8 and the auxiliary paper feed roll 2 l1.Additional printed copies may be fed out over the platen 228 in theusual manner. It is now apparent that each time a character is printedby operation of a type bar (not shown) against the platen 220,corresponding code marks will be made in a vertical line above thecharacter and at the rear of the page form. in addition to the usualfeed marks. It is to be noted that the feed marks lever l98-F, isinterposed between code mark levers l983 and [98-4. Although printing issuppressed during shift and unshift functions in both types of pageprinters described above, it should be remembered that the first codemark combination following the shift operation will show the presence orabsence of the sixth code mark according to the case position assumed bythe printer.

Referring now particulary to Figs. 12 to 19, the photoelectrictransmitting apparatus provided in the present invention will bedescribed. A pictorial representation of a portion of the rear of a pageform 240 to be scanned by the photoelectric transmitter is shown in Fig.17 with thecode marks appearing thereon corresponding to relatedcharacters appearing on the front of the page form. Numeral 258represents the base of the apparatus upon which is mounted a motor 25!for providing rotary movement of main shaft 252 by means of gears 253and 254. Shaft 252 is journaled on the upright supports 256 and 25'! andhas fixedly attached, thereto a scanning disc 258, shown in detail inFig. 16.

Extending across the, top of the apparatus is movable in the cylindricalor tube portion 266- of the projector. Upon oscillation of theprojector, as will later be described, sliding movement of lens element266 is produced by reason of the engagement of a pin 263 carried therebyin a slot 21! of a cross piece 2'52. Sliding movementg'pf lens element2E! is similarly produced lnl e'ngggement of pin 21; in slotjl'ifi ofcrqsspiec 216. It is to be understood that the tube por-'- tion 268 ofthe projector, at the places where en-' gaged by pins 269, 213, will beprovided with suitable clearances to permit the sliding move-- ment ofelements 266 and 261. Because of the construction just described above,the focal length of the projector 264 may be varied according to thearea of the page form 248 beingscanned as will later become moreapparent.

One end of the projector 264 is covered by a plate 211 having openings218-I to 218-6, 218-1 (Fig. 18) and an opening 218S which are adjacentto the scanning disc 258. The openings just mentioned are made narrowerthan the image received therethrough so that when a code mark or a feedmark is scanned it will completely cover the opening to which it isrelated. This further allows a slight misalignment between the projector264 and the code marks of page form 248.

At the top of the apparatus is a guideway 219 composed of a guidingplate 28| and the top plate'282 of the apparatus. Plate 28| is oftransparent material to allow viewing of the printed characters on thepage form. Plate 282 is slotted at 283 so as to expose one line of codemarks to a suitably mounted mirror 284. Light for the optical system isprovided by a fluorescent lamp 286 extending across the apparatus at thetop of the mirror 284. Mounted between plate 211 of projector 264 andscanning disc 258 is a thin opaque shutter 281 shown in detail in Fig.19 which is mounted on an armature 288 of a ma net 289. Shutter 281 ismovable to two different positions as will later appear. In one positionit will permit the passage of light for scanning purposes through feedhole opening 288F formed thereon, from opening 218-F of plate 211 and atthis time block all of the openings 218l to 218-6 and 218S. In the otherposition, projection 292 of shutter 281 is interposed in front of feedhole opening 218S and all the code mark openings are unblocked forscannin purposes.

With reference now to Fig. 16, the scanning disc 1 258 will be describedin more detail. Its purpose is to selectively control the passage oflight to a photoamplifier tube 293 suitably mounted in the apparatus.Scanning disc 258 consists of an opaque circular plate having arcuatetransparent areas 294-| to 2946, progressively arranged about the centerpoint at different radial posi: tions which are in line withcorresponding openings in plate 211 of projector 264. In' addition, anarcuate transparent area 284-8 is provided for the start impulse while acontinuous transparent ring 294-"F is provided for scanning of the feedmark. The start impulse is provided by painting a line the same color asthe page form across the underneath part of plate 282 adjacent the slot283. No arcuate transparent area is provided for the stop impulse sincethis corresponds to a markin impulse and at this time an opaque portionof disc 258 which lies between areas 294-6 and 294S will be presented inscanning position with respect to photoamplifier tube 293. Y

The mechanism for moving the free end of the 308,389 operable by arms3!! and 3l2 oif'arma-fi v ture.3l 3; c i i ;magnet8l4 actas a clutch toenable;

the rotation of a gear 301 with the gear 306. The previously describedgearing provides a, speed reduction for gear 301'.v Gear 391 is. inmesh. with a rack 311 which is suitably connected to projector 264 bymeansv of a pin 318. Thus, when. clutch magnet 314 is periodicallyenergized, gear -1 will drive the rack 311 to the left as viewed in Fig.14, causing the projector 264 to move also periodically to the left toscan a line of code marks as. will hereafter appear. Rack 311 isprovided, with rollers 320 which ride in the slotted guideway 325. Forreturning the projector 264. to the beginning of line position, av gear319 is provided which is also in mesh with the rack 3.1-1 andis, carriedrotatably about the shaft 393 on a sleeve 32!. When gear 391 drives rack311, seat 3H1 moves idly about the shaft 303, in a; counterclockwisedirection. Return movement of gear 319 is under the control of a singlerevolution clutch, indicated generally at 322 the operation of which isgoverned by a clutch magnet 3.23: in. a, manner well known in the art.Stop arm 32-4; is operable, under the, control of armature 326 of clutchmagnet. 323, as will; be; later described in. detail. When the clutch322. is released sleeve 326 rotates until a lug 3'21 carried therebyengages a lug 328 carried by the gear 3l9. When this occurs, gear 3l9.will rotate in a clockwise direction and drive rack 31 1 back to. its,beginning of line position. The length of the previous line scanneddetermines at. what point lug 321 will engage lug 3.218.. It is apparentthat when gear 391 drives the rack- 3l1, gear 319 will also be rotatedand lug 328 will move away from lug 3211-.

Suitably pivoted at 329 in the apparatus is a brake 33!, urged in. acounterclockwise direction ('Fig. 12 by; means of a. spring 332,, andcarrying brake material 333. which presses against the side. ofrack'3:!1 through. the opening in. guideway 325'. Arm. 3.4.2 of armature 313has an extension 334 which operates against one end of a lever 336pivoted at; 331, causing a projection 338 carried. at its other end tooperate against brake 33[ and: tree it; from rack3l1'when. clutchmagnet. 314 is energized. At this ime gear 319.- maydrive rack 3-H tothe left, as shown in Fig. 14. When the projector unit; is beingreturned to the beginning of line position, clutch magnet 323 willopcrate.- and sleeve 326 will be released for rotation asaexplained;Sleeve. 326 carries a. cam 339 which operates a follower'slide lever 34I which by pushing: against the shorter arm of brake 3'3l, also treesthe brake so that ear 319; may bepermitted to drive rack 3H to. thebeginning of the line position. Just before this position is: reachedcam 339: operates lever 341' and permits brake 33l. to.

i move to its braking position preventing the opti-- cal unit: frombeing jarred or rebounding. It; is apparent. then, as rack 31:1 is.operated, projector 26:4? will be pivoted and lens sections 266, 261willv slide in the tube 268 tov automatically adjust the focal length ofthe projector according to the area of the page form being scanned.

A description of the page form feeding mechanism will now be given. Onshaft 2152 is rigidly attached a gear 342, which is in meshv with asliding movementiatzeitherside:or the apparatus Shaft 36! supportsthe-pressure roller 33.2.

At onev end; shaft 344" 12 on brackets 356 andv 351' are members 358 and359 which support at their upper ends a pres-e; sure roller shaft 3.6lextending therebetween. The lower ends of members 358 and 359 areconnected by a cross rod 363 the middle portion of which has attachedthereto an armature 364. which is under the control of a magnet366.Compression springs 351 normally urge mem hers 358 and 359 to an upwardposition so that, pressure roller 352 is free of constantly rotatingfeedroll 354 and no feeding of the page form takes place. At this time abrake member 368 also supported from members 358 and 359 and havingbrake material 969 holds the paper from movement against the upperguidsway 28! as is shown clearly in Fig. 13. However, when; armature 364is attracted upon energization. of magnet. 366 members 353 and 359 arepulled downagainst the tension of springs 381, freeing brake member 368.from the page form and enabling pressure rollers. 362. to force the pageform 249 against. feed roll 3.54. At this time the. page form is. fedforward as will more readily hereinafter appear in connection with thedescription of the circuit arrangements.

Before a description of the first circuit arrangement is undertaken,attention is called to switch cams 369, 319, and 31! mounted on theconstantly rotating shaft 252 of the transmitting apparatus and to.contact bank 543 at the right side of Fig. 14. It is to be understood ashas been pointed out. before, that the apparatus is adapted to be usedeither for transmission. of a, six unit. code or with somemodifications. for an arrangement wherein six unit code signals areconverted into five unit. code signals with automatically inserted shiftsignals.

The circuitv arrangement for transmitting six unit code signals will nowbe described with particular reference to Fig. 20. Numeralv 31-5represents an alternating current power source which furnishes power forthe motor 251 and for the primary 316 of a transformer 311. Power forthe illumination of the previously identified fluorescent lamp 286 isprovided from secondary 318 of transformer 311 by means of rectifierfilter 3.89. The other secondary 319, by means of rectifiers 38I,inductances, 382, and condensers 383, furnish current for operation ofphotoamplii fier tube 293 and the primary of a transformer 384. Thesecondary 319 of transformer 311 is. tapped at its midpoint andgrounded. The elements of photoamplifier tube 293 are connected to tapsof a resistancev 383 to provide varying. potentials with the mostpositive potential applied to the element adjacent collector plate 381.As the code marks are scanned and light is impinged on thephotoamplifier tube 293,.if'

K unprinted areas are scanned,v there is a substantially' uniformcurrent in the primary of trans former 384. If all areas scanned insuccession have printed code marks, again a substantially uniformcurrent flows in the primary of transformer 394 but in this case it isof a lower value.

Under either of the above steady state conditions just outlined above,no current will flow in the secondary of transformer 384. The secondaryof transformer 38% is connected to the grid of tube 388, the plate ofwhich is in series with;

